package 暴力枚举;

/**
 * @PackageName: leetCode
 * @ClassName: LeetCode14
 * @Author: chen jinxu
 * @Date: 2022/8/10 22:22
 * @Description: //最长公共前缀
 *
 * 编写一个函数来查找字符串数组中的最长公共前缀。
 * 如果不存在公共前缀，返回空字符串 ""。
 *输入：strs = ["flower","flow","flight"]
 * 输出："fl"
 *  输入：strs = ["dog","racecar","car"]
 * 输出：""
 * 解释：输入不存在公共前缀。
 *
 * 1 <= strs.length <= 200
 * 0 <= strs[i].length <= 200
 * strs[i] 仅由小写英文字母组成
 */
public class LeetCode14 {
    public static void main(String[] args) {
        System.out.println(longestCommonPrefix(new String[] {"flower","flow","flight"}));
        System.out.println(longestCommonPrefix(new String[] {"dog","racecar","car"}));
        System.out.println(longestCommonPrefix(new String[] {}));
    }

    public static String longestCommonPrefix(String[] strs) {
        if (strs == null || strs.length == 0) {
            return "";
        }
        String prefix = strs[0];
        int len = strs.length;
        for (int i = 1; i < len; i++) {
            prefix = longestCommonPrefix(prefix, strs[i]);
            if (prefix.length() == 0) {
                break;
            }
        }
        return prefix;
    }
    public static String longestCommonPrefix(String str1, String str2) {
        int length = Math.min(str1.length(), str2.length());
        int index = 0;
        while (index < length && str1.charAt(index) == str2.charAt(index)) {
            index++;
        }
        return str1.substring(0, index);
    }

}
